# How Much Do You Weigh? (Blind Calculator Average)

Participants pass a single calculator to compute the exact arithmetic average of a sensitive number while keeping every individual submission private. A secret starting offset conceals raw values so the team can discuss accurate baseline data without personal exposure.

**Time:** 15 minutes. UWT suggested standard plan (15 minutes). The source provides an open-ended structured sharing mechanic without fixed minute allotments.
**People:** 4 to 24. Whole group in a single passing circle for 4 to 12 participants. For 13 to 24 participants, divide into two equal circles of roughly equal size (6 to 12 each).

## Choose this exercise

**Purpose:** Calculate an accurate group average for sensitive or taboo numbers without disclosing any participant's individual data.
**Use it when:** Use when a team or peer group needs an honest baseline average on a sensitive metric such as daily consulting rates, weekly hours, salary targets, or survey ratings, but fear of peer comparison blocks honest self-reporting.
**Skip it when:** Skip when the sample size is under four people, because individual numbers can be roughly deduced, or when the underlying data does not lend itself to a meaningful arithmetic mean.

## Materials and tools

- 1 standard handheld calculator with clear display per circle of 4 to 12 participants
- 1 index card and pen for each seed participant to privately record their offset number
- Flipchart or whiteboard and dry-erase markers for recording the final group total and average

## Before participants arrive

1. Confirm the calculator battery works and the clear button functions properly.
2. Decide on the exact numeric question, the unit of measurement, and whether decimals or whole numbers are expected.
3. Arrange seating so the calculator can be passed smoothly from hand to hand in a circle.

## Say this to open

We need an accurate baseline for our discussion, but sensitive personal numbers can feel awkward or risky to share openly. We will use a blind calculation technique that guarantees complete privacy for every person. One person enters a secret offset number first so nobody sees any raw figures. Each of you will add your number to the running sum and pass it along. At the end, we subtract the secret offset, divide by the count of contributors, and get our exact group average without anyone revealing their private number.

## How to run it

### 1. Frame metric and start offset (3 minutes)

State the exact numeric prompt (for example: 'Enter your standard billable daily consulting rate in dollars, rounded to the nearest fifty'). Hand the calculator, an index card, and a pen to Participant 1. Participant 1 privately punches in a secret four-digit seed number, writes it on their card, conceals the card, presses the '+' key, and hands the calculator to Participant 2. Emphasize that Participant 1 must not reveal the seed number.

### 2. Accumulate private entries (5 minutes)

Each person in turn enters their personal number, presses the '+' key, and passes the calculator to the next person. Because the screen displays the running sum of the seed and earlier entries, no one can discern the specific value just entered. Anyone opting out keys '0', presses '+', and hands the calculator on while flashing a pre-arranged discreet non-verbal cue (such as tapping the back of the calculator twice or catching the facilitator's eye) so the facilitator tallies the exact number of active contributors.

### 3. Reconcile seed and compute average (3 minutes)

When the calculator returns to Participant 1, Participant 1 enters their own actual personal data point, presses the '+' key, presses the '-' key, enters the secret four-digit seed number from their card, and presses the '=' key. The display now shows the exact grand total of all participant inputs. The facilitator records the grand total on the board, divides it by the total count of active contributors, and announces the group average. If using two circles, sum both clean totals and divide by total active contributors across both circles.

### 4. Debrief the aggregate data (4 minutes)

Lead a focused debrief on the resulting average. Invite 3 to 4 participants to share observations on how the aggregate figure compares to their expectations, without asking anyone to state where they sit relative to the line.


## Debrief questions

- How does this aggregate average compare with what you expected before we ran the numbers?
- Knowing only the group average and not who entered what, what patterns or disparities does this suggest about our current practices?
- How did having total numerical anonymity affect your willingness to enter an honest figure?

**Finished output:** A verified mathematical group total and average for a sensitive metric, recorded on a shared board, with individual figures kept private.

## Remote

Use an anonymous digital polling tool or private online form that does not collect email addresses. Alternatively, run the offset mechanic via direct chat: in groups up to 12, Participant 1 messages (Seed + Rate 1) privately to Participant 2, who adds their rate and messages Participant 3, ending with Participant 1 subtracting the seed. For 13 to 24 participants online, run two parallel chat chains of equal size and combine the final net sums before dividing by active contributors.

## Hybrid

Provide remote participants a dedicated anonymous web form or private direct-message link to an off-camera operator, while in-room participants pass the physical calculator. The operator adds the remote batch total into the physical calculator before Participant 1 removes the seed, ensuring equal anonymity across both groups.

## Access and participation choices

- Anyone may opt out of contributing data without public disclosure by entering '0', pressing '+', and giving the discreet pass cue so the divisor stays accurate.
- For participants with fine motor or vision differences, offer a large-button calculator, or allow them to enter their value privately into an accessible digital form.

## If the session gets stuck

**A participant accidentally hits the 'Clear' (C or AC) button instead of '+', wiping out the running sum.**

Pause immediately. Hand the calculator back to Participant 1, have them re-enter the seed from their card, and re-circulate the calculator around the circle. Remind everyone to press only digits and the '+' key.

**Participant 1 forgets their original seed number.**

Prevent this during setup by requiring Participant 1 to write the four-digit seed on a private paper card tucked away safely. If lost, restart the sequence immediately.


## Terms used here

- Seed number: A random starting number entered before any real data so the calculator display never shows raw individual entries.
- Framegame: A reusable activity structure or shell that can hold different content topics while keeping the same basic mechanics.

## Sources and adaptation

Observed in Play for Performance (June 2004), published by Workshops by Thiagi, Inc., featuring the structured sharing activity 'How Much Do You Weigh?'.

Retained the core blind-calculator structured sharing mechanic published in Thiagi's Play for Performance (June 2004) under the article 'How Much Do You Weigh?'. UWT added explicit circle split arithmetic for 4 to 24 participants, step-by-step facilitation timing (15 minutes total), a discreet tally cue for opt-outs to preserve mathematical divisor accuracy, parallel remote chat chain instructions, and debrief prompts.

[The Thiagi Group](http://thiagi.net/archive/www/pfp/IE4H/june2004.html)

[The Thiagi Group](https://thiagi.net/archive/www/pfp/IE4H/june2004.html)

Current run sheet: https://unitedwetransform.com/exercises/pfp-june-2004/